I can't agree.
Combat is better yes, but I actually feel music, environment, pacing is better on Doom 2016. I also think Eternal has more going on at 60 fps, but the graphics feel worse to me, they're stretching the same budget so individual assets were downgraded or use more trickery than before (this on PS4).
Not to say the game was perfect with the clear "arena" system being so blatant and all, but it felt really good, the challenges too whereas on Eternal it just lacks that pull. Eternal feels like a chore, and the plataforming, albeit more in the lines of how I remember original Doom to be, just not fun. Some elements don't feel like doom and instead like quake, but I digress as if I enjoyed them I'd be all over the moon.
It's still a very good game, but I felt it was a step down. This said, I still have to finish it, but that says a lot about the game, at least for me. With Doom 2016 I just couldn't put it down.